1. Field of the Invention
This invention relates to a method and apparatus for encrypting and decrypting data stored in a magnetic bubble domain memory by permuting or skewing selected word bits by predetermined amounts.
2. Description of the Prior Art
The recent and rapidly expanding development of magnetic bubble domain technology holds the promise of providing very fast, efficient, and low cost data memories in the near future. With the anticipated proliferation of such memory devices, the security of the data stored from unauthorized recovery thus becomes an important consideration.
The general proposition of developing a cipher by key permutations of clear data to implement a security function is known in the art. See, for example, the article by R. O. Skatrud in the Proceeding of the Fall Joint Computer Conference, 1969, at page 111. In view of the unique nature and characteristics of magnetic bubble domain memories, however, these known security techniques are not readily adaptable thereto and present special problems. It is a solution of these problems to which this invention is generally addressed.